Reference Ranges for Third-Trimester Maternal Cardiovascular Function Parameters Measured in Normotensive Pregnant Women Using a Noninvasive Cardiac Output Monitor: A Study Based on Data From the Prospective PEACH Cohort Study

( BJOG. 2024;131:463–471. doi: 10.1111/1471-0528.17667) Changes to the cardiovascular system during pregnancy are expected; however, maladaptation is indicative of pregnancy-related cardiovascular disease and should be screened for. Invasive catheterization and echocardiography have traditionally been the tools used for detection of such conditions; however, more noninvasive alternatives have become available, such as the Ultrasound Cardiac Output Monitor 1A (US-COME-1A). This device uses continuous-wave Doppler ultrasound and has been used in pregnant patients with similar results to third trimester echocardiography. Clinicians would benefit further from reference ranges to make this a more useful tool; thus, this study seeks to provide such reference ranges for cardiac output (CO), stroke volume (SV), and systemic vascular resistance (SVR) in singleton pregnancies.